Question

p-Hydroxybenzaldehyde does not undergo Cannizzaro reaction. Explain.

Answer 1

In Basic medium, $\stackrel{\ominus }{O}H$ takes proton of the Hydroxy group leaving behind $O^{\ominus }$, which is the strong activating group $(+R+I)$. When $O^{\ominus }$ come in Resonance with an aldehyde group, the carbonyl carbon is no longer electrophilic. So, $\stackrel{\ominus }{O}H$ cannot attack there and hence Reaction will not proceed.